Design and Fabrication of a One-Transistor/One-Resistor Nonvolatile Binary Content-Addressable Memory Using Perpendicular Magnetic Tunnel Junction Devices with a Fine-Grained Power-Gating Scheme
Design and Fabrication of a One-Transistor/One-Resistor Nonvolatile Binary Content-Addressable Memory Using Perpendicular Magnetic Tunnel Junction Devices with a Fine-Grained Power-Gating Scheme
复制标题
使用具有细粒度功率门控方案的垂直磁隧道结器件设计和制造一晶体管/一电阻器非易失性二进制内容寻址存储器
DOI：
--
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
T. Hanyu
中科院分区：
文献类型：
--
作者：
S. Matsunaga;M. Natsui;S. Ikeda;K. Miura;T. Endoh;H. Ohno;T. Hanyu
提出了一种基于垂直磁隧道结（P-MTJ）的单管单阻（1 T-1 R）二进制内容可寻址存储器（CAM），用于高密度非易失性CAM。所提出的CAM单元通过检测“单元电阻”的差来执行输入位与对应的存储位之间的相等搜索操作，其中单元电阻由一个金属氧化物半导体（MOS）晶体管和一个P-MTJ器件的串联连接来确定。该电路结构使得可以在0.14 μm互补MOS（CMOS）/P-MTJ工艺中实现单元尺寸为1.25 μm2的紧凑型非易失性CAM单元电路。此外，以位串行方式的相等搜索操作被用于大大降低所提出的CAM单元阵列中的活动率，因为CAM中的大多数失配字仅由字电路中的比较结果的几个较高位来检测。通过采用位级细粒度功率门控技术，实现了64位× 128字非易失性CAM的高密度化，同时保持了低的搜索能量，单元阵列的激活率低于3.1%。
A perpendicular magnetic tunnel junction (P-MTJ)-based one-transistor/one-resistor (1T–1R) binary content-addressable memory (CAM) is proposed for a high-density nonvolatile CAM. The proposed CAM cell performs an equality-search operation between an input bit and the corresponding stored bit by detecting the difference of a “cell resistance”, where the cell resistance is determined by the series connection of one metal–oxide–semiconductor (MOS) transistor and one P-MTJ device. This circuit structure makes it possible to implement a compact nonvolatile CAM cell circuit with 1.25 µm2 of a cell size in a 0.14 µm complementary MOS (CMOS)/P-MTJ process. Moreover, the equality-search operation in a bit-serial fashion is used for great reduction of the activity rate in the proposed CAM cell array, since most of the mismatched words in the CAM are detected by just several higher bits of comparison results in the word circuits. By applying a bit-level fine-grained power gating scheme, a fabricated 64-bit × 128-word nonvolatile CAM achieves high density with maintaining low search energy under 3.1% of activity rate in the cell array.